Lifestyle Medicine, Main blog page, Other topics

Healthy sustainable eating

I am really pleased to see a growing movement of people who are keen to minimise their negative impact on the environment. Be it taking a keep-cup to the coffee shop, a reusable water bottle to work or a canvas tote bag shopping, progress is being made towards a more sustainable daily routine. One aspect of our lives, however, has a large impact to our planet – the food we eat. Today I thought I’d tackle the topic of how to eat both sustainably and healthily. This is a huge topic, so I’ve tried to keep it brief. This will inevitably mean I have missed out some areas, and if these are of interest to you let me know and I can try to cover them another time.

Firstly, what does sustainable eating actually mean? We need to think about everything that encompasses getting those pieces of food onto our plates; greenhouse gas emissions, land use, water consumption, impact on biodiversity, and much more.

One definition from the Food and Agriculture Organization of the United Nations is:

Sustainable diets are those diets with low environmental impacts which contribute to food and nutrition security and to healthy life for present and future generations. Sustainable diets are protective and respectful of biodiversity and ecosystems, culturally acceptable, accessible, economically fair and affordable; nutritionally adequate, safe and healthy; while optimising natural and human resources.” 1.

Sadly, the pressure our food system poses on the environment is huge, and the demand for food production is ever growing along with the increasing global population 2. If the current methods of production are used, meeting this increased demand will be unsustainable.

Nature published a well-publicised paper recently which stated:

By 2050 these dietary trends, if unchecked, would be a major contributor to an estimated 80 per cent increase in global agricultural greenhouse gas emissions from food production and to global land clearing. Moreover, these dietary shifts are greatly increasing the incidence of type II diabetes, coronary heart disease and other chronic non-communicable diseases that lower global life expectancies.” 3

Processed foods can have low greenhouse gas emissions, but be high in empty calories, fats and carbohydrates. Therefore, swapping to a sustainable way of eating doesn’t necessarily lead to a healthy lifestyle.

This study showed that relative to an omnivorous (the global-average) diet, a vegetarian, pescatarian or Mediterranean diet had reduced rates of type 2 diabetes, cancer and lower mortality rates3. Things these three diets have in common is a higher consumption of vegetables, nuts, pulses fruits and a lower proportion of calories made up of ‘empty calories’ and meat. ‘Empty calories’ are those which arise from refined animal fats, oils, alcohols and sugars3.

Eating less than 500 grams of cooked red meat a week has been shown to reduce the risk of colorectal cancer4. The effect is most pronounced when reducing processed meat. Processed foods contain more salt and saturated fat. Reducing these not only lowers colorectal cancer risk but therefore also improves your cardiovascular health4.

Plant-based food products are not only healthy for us, they have lower greenhouse gas emissions when compared to animal based foods3. For example, per gram of protein, beef and lamb emit 250 times as much greenhouse gases as legumes3.


The nature paper has a really great graph on page 2 relating to greenhouse emissions per serving, calorie or gram of protein for different land-animal, fish and plant-based food sources.

This emphasises the significant environmental impact of raising livestock. It is not only the release of greenhouse gas which effects the environment, you need to consider the use of fertiliser and pesticides (which can run-off into streams), production of feed, land-use and water consumption. The latter, water consumption, is far greater for livestock than vegetable and grain production. It has been estimated that 1kg of grain needs 1000 litres to be produced, compared to 43 000 litres for 1 kg of beef, taking into account both the animal and its feed5. Poultry is the meat source with the smallest environmental impact, followed by pork4.

Growing livestock isn’t all about the meat. There are numerous animal products in our food systems. Take diary for example, what are the nutrition and sustainability issues here?

Dairy farms do produce greenhouse gases, but less than the beef industry5. Overall, food production leads to 18-20% of UK greenhouse gas emissions6, dairy farming accounts for less than 2%7.


There is a wide variety of dairy alternatives on the market now. Each has its own relationship with the environment. Almond milk, for example emits only 1/10th of the amount of greenhouse gases needed to produce cows milk8 but uses 17 times more water. Oat milk generates less greenhouse gases but causes increased acidification of our planet’s water9. Soya milk generates less greenhouse gases, has less land use and damages water systems less when compared to cow’s milk10.

So that’s sustainability of plant-based dairy alternatives, but what about their nutrition content?

  • There isn’t an alternative that has the same nutritional profile as diary milk. Out of the plant-based milks, soya is the most similar.
  • Most plant-based milks have low protein, with soya and hemp milk being the most protein dense.
  • Micronutrients also need to be considered. As these are often lacking naturally, it is good to look out for those fortified with key micronutrients such as vitamin B12 and calcium.
  • Unsweetened versions have better sugar profiles as standard versions often have added sugars.

There’s a great paper written about plant-based milks called ‘Plant-based milk alternatives an emerging segment of functional beverages: a review’.

To sum up, diary production is less harmful to the environment than the beef industry and plant-based alternatives have their own environmental considerations. If you prefer plant-based, aim for fortified, unsweetened versions.

The Double Pyramid: Healthy food for People and Sustainable for the planet has been developed which clearly shows foods which are both healthy and sustainable:

 double pyramid.png

Picture reference: 11

Personally, I am adopting a more plant-based diet. Whilst I am not vegan, I have the upmost respect for those who are for ethical reasons. I am trying to eat in a more sustainable way all the time. I think any change, however small, towards a more sustainable lifestyle should be supported and seen positively.

Between my reading and own experience, I’ve come up with a few simple tips for you to eat healthily in a more sustainable way.

My tips:

  • Plant-based focus – any small change you can do in this direction will be beneficial for both your health and the planet. If cutting out animal products isn’t going to suit your lifestyle consider eating smaller quantities and ensure it’s good quality produce.
  • Buy local & seasonal – buying food with less carbon emissions associated with them due to reduced transportation and refrigeration. Also have the bonus of supporting your local community.
  • Avoid highlyprocessed foods – a general rule of thumb, the shorter the list of ingredients the better.
  • Buy food which is grown in a sustainable and ethical manner – this is easiest to achieve by buying foods which are certified. For oily fish for example, only eat that certified by the Marine Stewardship Council (MSC).
  • Minimise food waste – food waste is staggering. A third of all food produced is wasted each year12. Tips to minimise your food waste:
    • Food prep – big batch cooking uses up fresh ingredients and you can eat leftovers for easy work lunches the next day or pop them in the freezer.
    • Use your freezer – don’t just chuck things away when they’re going off. Think ahead and put food you know you wont use in time in the freezer. For example, cut your fresh loaf of bread in half, keep half out and freeze the other. Frozen fruit and vegetables are so convenient and a great way of adding nutritional value quickly to a meal. If you live alone or often cook for one this saves eating the same bag of carrots etc for a week straight!
    • Try to by fresh produce NOT in a plastic wrapper. I love going to my local greengrocers as all the fruit and veg are piled up in cardboard boxes for you to take your pick from and if you want you can pop them in paper bags. Many supermarkets sadly still insist on wrapping food products that have their own skins in plastic bags! Go for the loose produce if possible.



  • Make a shopping list – if you plan your meals and know what you need to make them you’re less likely to end up with lots of food that doesn’t really go together and wasting half of it. Stock up on cupboard staples such as legumes and pulses which don’t go off for ages and can easily be used to whip up a hap-hazard meal when needed.
  • Don’t bin food waste, compost it! – Unfortunately, this isn’t supported by every council but if you have a garden or allotment you can buy your own compost bin for some home-grown fertiliser.


I hope you enjoyed reading this blog, it’s such a big topic and I know I only covered some elements. I hope you find my tips useful and feel inspired to enjoy eating a healthy and sustainable diet.

Emma x



  1. Dietary guidelines and sustainability | Food-based dietary guidelines | Food and Agriculture Organization of the United Nations. Available at: (Accessed: 25th October 2018)
  2. Healthy, sustainable diets – what are the issues? – British Nutrition Foundation. Available at: (Accessed: 25th October 2018)
  3. Tilman, D. & Clark, M. Global diets link environmental sustainability and human health. Nature 515, 518–522 (2014).
  4. Livsmedelsverket. Find your way to eat greener, not too much and be active. (2015).
  5. Gerber et al. Tackling climate change through livestock: A global assessment of emissions and mitigation opportunities. (2013).
  6. Macdiarmid, J. I. et al. Sustainable diets for the future: can we contribute to reducing greenhouse gas emissions by eating a healthy diet? Am. J. Clin. Nutr. 96, 632–639 (2012).
  7. Food Climate Research Network (FCRN) | Knowledge for better food systems. Available at: (Accessed: 27th October 2018)
  8. Ho, J., Maradiaga, I., Martin, J., Nguyen, H. & Trinh, L. Almond Milk vs. Cow Milk Life Cycle Assessment. (2016).
  9. Röös, E., Patel, M. & Spångberg, J. Producing oat drink or cow’s milk on a Swedish farm — Environmental impacts considering the service of grazing, the opportunity cost of land and the demand for beef and protein. Agric. Syst. 142, 23–32 (2016).
  10. Poore, J. & Nemecek, T. Reducing food’s environmental impacts through producers and consumers. Science 360, 987–992 (2018).
  11. Eating Better – What are healthy, sustainable diets? Available at: (Accessed: 25th October 2018)
  12. Key facts on food loss and waste you should know! | SAVE FOOD: Global Initiative on Food Loss and Waste Reduction | Food and Agriculture Organization of the United Nations. Available at: (Accessed: 27th October 2018)


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